CN100474847C - Signal transmission circuit, electronic device, cable, and connector - Google Patents
Signal transmission circuit, electronic device, cable, and connector Download PDFInfo
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- CN100474847C CN100474847C CN200510098776.2A CN200510098776A CN100474847C CN 100474847 C CN100474847 C CN 100474847C CN 200510098776 A CN200510098776 A CN 200510098776A CN 100474847 C CN100474847 C CN 100474847C
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- H05K9/00—Screening of apparatus or components against electric or magnetic fields
- H05K9/0066—Constructional details of transient suppressor
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H7/00—Multiple-port networks comprising only passive electrical elements as network components
- H03H7/38—Impedance-matching networks
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H7/00—Multiple-port networks comprising only passive electrical elements as network components
- H03H7/42—Networks for transforming balanced signals into unbalanced signals and vice versa, e.g. baluns
- H03H7/425—Balance-balance networks
- H03H7/427—Common-mode filters
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
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Abstract
A signal transmission circuit has first to fourth inductors, and first and second varistors. The first and second inductors are magnetically coupled to each other. The first varistor is located posterior to the first inductor and is electrically connected in parallel to the first inductor. The third inductor is located between the first inductor and the first varistor and is electrically connected in series to the first inductor. The second varistor is located posterior to the second inductor and is electrically connected in parallel to the second inductor. The fourth inductor is located between the second inductor and the second varistor and is electrically connected in series to the second inductor.
Description
Technical field
The present invention relates to a kind of signal circuit and electronic equipment, cable and connector with this signal circuit.
Background technology
As one of the mode of transmission of digital signals between the electronic equipment differential transmission mode is arranged.So-called differential transmission mode is the rightabout digital signal of input in a pair of circuit, can offset radiation noise, the extraneous noise that is produced by holding wire by differential transmission.Offset extraneous noise minimizing noise jamming and just can send signal, simultaneously,, also have and to shorten signal increase, fall time, improve the advantage of signaling rate because signal is little amplitude with little amplitude.
Interface specification as this differential transmission mode of use has USB (Universal Serial Bus USB), IEEE1394, LVDS (Low Voltage Differential Signaling Low Voltage Differential Signal), DVI (Digital Video Interface digital visual interface), HDMI (High-Definition Multimedia Interface HDMI (High Definition Multimedia Interface)) etc.HDMI can transmit the more interface of multiple digital signal in the middle of them, be again can be in the source (Source) machine (for example, DVD player and set-top box etc.) and receive the high-speed interface that transmits incompressible digital signal between (Sink) machine (for example, Digital Television and projector (proiector) etc.).If adopt HDMI, can high-speed transfer picture signal and voice signal with a cable.
But, be accompanied by the high speed of transmission speed, even the small deviation of differential wave also can produce noise between the holding wire.In order to address this problem, motion insert the transmission circuit (for example, opening communique 2001-No. 85118) that common mode choke alleviates noise by interface with reference to the Japan Patent spy at cable etc.
In high speed interfaces such as HDMI, in order to realize high speed, the structure of IC self is with respect to ESD (Electrostatic Discharge; Static discharge) becomes fragile.So, the requirement of the ESD countermeasure among the high speed transmission system IC is improved, use rheostat (varistor), Zener diode capacitive elements such as (Zener diode) parts as the ESD countermeasure.
But, reaffirmed if will insert transmission line as the capacitive element of ESD countermeasure parts, be sent to the signal, particularly high-frequency (more than the 200MHz) of this transmission line or the problem that high-speed pulse ripple signal can produce reflection, decay one class.This is because when capacitive element is inserted transmission line, and the capacitive component with capacitive element descends the characteristic impedance (impedance) that is inserted with the capacitive element position in the transmission line, causes this position impedance not match.When having the unmatched part of impedance in transmission line, because the high-frequency composition of signal causes reflection in the unmatched part of characteristic impedance, return loss (return loss) takes place.Its result can cause signal significantly to decay.In addition, produce noise by being reflected in the unwanted radiation meeting that produces in the transmission line.
In HDMI, the setting of the characteristic impedance of transmission line (TDR specification) is defined as 100 Ω ± 15% (High-Definition Multimedia Interface SpecificationVersionl.1).
Summary of the invention
Even the purpose of this invention is to provide a kind of when using capacitive element as the ESD countermeasure, the signal circuit, electronic equipment, cable and the connector that also can the suppression characteristic impedance descend.
Signal circuit of the present invention has: mutual magnetic-coupled first and second inductor; Be positioned at the back segment of first inductor, first capacitive element that is connected in parallel with this first inductor electricity; Be positioned at the back segment of second inductor, second capacitive element that is connected in parallel with this second inductor electricity; Between first inductor and first capacitive element, the 3rd inductor that is connected in series with the first inductor electricity; Between second inductor and second capacitive element, the 4th inductor that is connected in series with the second inductor electricity.
Signal circuit of the present invention by first～the 4th inductor, can suppress the decline of the characteristic impedance that caused by first and second capacitive element.
Preferably further have: be positioned at the back segment of first capacitive element, and the 5th inductor that is connected in series with the 3rd inductor electricity; Be positioned at the back segment of second capacitive element, and the 6th inductor that is connected in series with the 4th inductor electricity.At this moment, can further suppress the decline of the characteristic impedance that causes by first and second capacitive element.
Electronic equipment of the present invention, cable and connector have above-mentioned signal circuit.
Respectively according to electronic equipment of the present invention, cable and connector, as mentioned above, can suppress the decline of the characteristic impedance that causes by first and second capacitive element.
According to the present invention,, also can provide the signal circuit, electronic equipment, cable and the connector that can the suppression characteristic impedance descend even when using capacitive element as the ESD countermeasure.
According to the following detailed description that provides and with reference to accompanying drawing, can be expressly understood the present invention more, but the present invention is not limited to this.
According to the clear more range of application of the present invention of following detailed description meeting.Yet, being to be understood that these describe in detail and particular example just illustrates preferred implementation of the present invention, those skilled in the art can not change the spirit and scope of the invention from these detailed descriptions and carry out change miscellaneous.
Description of drawings
Fig. 1 is the schematic diagram of the signal circuit of expression first execution mode.
Fig. 2 is the circuit diagram of the signal circuit of expression first execution mode.
Fig. 3 is the schematic diagram of explanation common-mode filter action.
Fig. 4 is the schematic diagram of variation of the signal circuit of expression first execution mode.
Fig. 5 is the schematic diagram of variation of the signal circuit of expression first execution mode.
Fig. 6 is the schematic diagram of variation of the signal circuit of expression first execution mode.
Fig. 7 is the circuit diagram of the signal circuit of expression second execution mode.
Fig. 8 is used to illustrate the figure that measures environment according to the TDR method.
Fig. 9 is the figure that is used to illustrate according to the assay method of TDR method.
Figure 10 is the line chart of expression according to TDR method measurement result.
Figure 11 is the line chart of expression according to TDR method measurement result.
Figure 12 is the line chart of expression according to TDR method measurement result.
Embodiment
Below, the preferred forms that present invention will be described in detail with reference to the accompanying.In addition, in explanation, use identical symbol, and omit repeat specification for key element with identical element or identical function.
As shown in Figure 1, Digital Television 1 and DVD player 2 connect with HDMI cable 3.HDMI cable 3 is to use the cable of differential transmission mode, has binding post 5,6 (connector).The binding post 5 of HDMI cable 3 is connected with the efferent of DVD player 2.The binding post 6 of HDMI cable 3 is connected with the input part of Digital Television 1.Digital signal by DVD player 2 outputs is sent to Digital Television 1 at a high speed by HDMI cable 3.
Digital Television 1 has signal circuit SC1 at its input part.As shown in Figure 2, signal circuit SC1 comprises: have the common-mode filter 10 of magnetic-coupled first and second inductor 11,12 mutually; The the 3rd and the 4th inductor 21,22; First and second rheostat 31,32.Common-mode filter 10 comprises: the input and output terminal 13,14 that is connected with first inductor 11; The input and output terminal 15,16 that is connected with second inductor 12.The input terminal 13,15 of common-mode filter 10, the binding post 6 by HDMI cable 3 is connected with the input part of Digital Television 1, is connected with the corresponding terminal of binding post 6.
The structure and the action of common-mode filter 10 are described with reference to Fig. 3.Fig. 3 is the skeleton diagram of the action of explanation common-mode filter 10.
Common-mode filter 10 twines some circles by 2 leads 17,18 with mutual insulating and constitutes on FERRITE CORE 19.Lead 17 constitutes first inductor 11, and lead 18 constitutes second inductor 12.The shape of FERRITE CORE 19 is not limited to ring-type as shown in the figure.
In the present embodiment, at signal, use common-mode filter 10 down at differential mode (differential mode).In differential mode, shown in (a) among Fig. 3, signal SI signal in the opposite direction is transfused to lead 17,18.Is rightabout magnetic flux by each lead 17,18 at magnetic flux F1, the F2 that FERRITE CORE 19 produces, and plays a part mutual elimination.So the almost impedance (inductance) that is produced less than the magnetic field MF that is produced by lead 17,18 is not so signal SI almost is output damply.
On the other hand, at common-mode noise CN, under common-mode state, use common-mode filter 10.Shown in (b) among Fig. 3, in common-mode state, common-mode noise CN is in the equidirectional generation of lead 17,18.So, be the identical magnetic flux of direction by each lead 17,18 at magnetic flux F1, the F2 that FERRITE CORE 19 produces, play a part mutual enhancing.So the impedance (inductance) that the magnetic field MF that is produced by lead 17,18 is produced uprises, hardly output common mode noise CN.Like this, common-mode filter 10 just can make noise attentuation.
Next with reference to Fig. 2.The 3rd inductor 21 has input and output terminal 23,24.The input terminal 23 of the 3rd inductor 21 is connected with the lead-out terminal 14 of common-mode filter 10.The 3rd inductor 21 is connected in series with first inductor, 11 electricity.The 3rd inductor 21 and first inductor 11 do not have substantial magnetic coupling.First rheostat 31 has input and output terminal 33,34.The input terminal 33 of first rheostat 31 is connected with the lead-out terminal 24 of the 3rd inductor 21.The lead-out terminal 34 of first rheostat 31 is connected with earthing potential.Thus, first rheostat 31 is positioned at the back fragment position of first inductor 11 and the 3rd inductor 21, and is connected in parallel with this first inductor 11 and the 3rd inductor 21 electricity.The 3rd inductor 21 is between first inductor 11 and first rheostat 31.
The 4th inductor 22 has input and output terminal 25,26.The input terminal 25 of the 4th inductor 22 is connected with the lead-out terminal 16 of common-mode filter 10.The 4th inductor 22 and second inductor, 12 electricity are connected in series.The 4th inductor 22 and second inductor 12 do not have substantial magnetic coupling.Second rheostat 32 has input and output terminal 35,36.The input terminal 35 of second rheostat 32 is connected with the lead-out terminal 26 of the 4th inductor 22.The lead-out terminal 36 of second rheostat 32 is connected with earthing potential.Thus, second rheostat 32 is positioned at the back fragment position of second inductor 12 and the 4th inductor 22, and is connected in parallel with this second inductor 12 and the 4th inductor 22 electricity.The position of the 4th inductor 22 between second inductor 12 and second rheostat 32.
As common-mode filter 10, for example, the common-mode filter that the ACM series that can use TDK Corp. to produce is comprised.As first and second rheostat 31,32, for example, the stacked chip rheostat that the AVR series that can use TDK Corp. to produce is comprised.
In aforesaid first execution mode, leading portion at first and second rheostat 31,32 inserts common-mode filter 10 (first and second inductor 11,12), simultaneously, between common-mode filter 10 and first and second rheostat 31,32, insert the 3rd and the 4th inductor 21,22 respectively.Thus, can suppress the characteristic impedance that caused by first and second rheostat 31,32 descends.
In the first embodiment, the leading portion at first and second rheostat 31,32 inserts common-mode filter 10.Thus, the signal from DVD player 2 outputs can be accompanied by extraneous noise, hardly by HDMI cable 3 and signal circuit SC1 input digit TV 1.
The structure of variation of the signal circuit SC1 of first execution mode then, is described based on Fig. 4～Fig. 6.What Fig. 4～Fig. 6 represented is the variation of the signal circuit of first execution mode.
In the variation that Fig. 4 represents, HDMI cable 3 has signal circuit SC1.
In the variation that Fig. 5 represents, DVD player 2 has signal circuit SC1 at its efferent.
In the represented variation of Fig. 6, the binding post 6 (connector) of HDMI cable 3 has signal circuit SC1.Also can have the signal circuit SC1 that signal circuit SC1 replaces the binding post 6 of HDMI cable 3 to have by the binding post 5 (connector) of HDMI cable 3.
Represent in any variation at Fig. 4～Fig. 6, can be by the decline of first and second rheostat 31,32 suppression characteristic impedances.
(second execution mode)
The structure of the signal circuit of second execution mode then, is described based on Fig. 7.What Fig. 7 represented is the circuit diagram of the signal circuit of second execution mode.
The 5th inductor 41 has input and output terminal 43,44.The input terminal 43 of the 5th inductor 41 is connected with the lead-out terminal 24 of the 3rd inductor 21.The 5th inductor 41 and first inductor 11 and the 3rd inductor 21 electricity are connected in series.Thus, the 5th inductor 41 is positioned at the back fragment position of first rheostat 31.
The 6th inductor 42 has input and output terminal 45,46.The input terminal 45 of the 6th inductor 42 is connected with the lead-out terminal 26 of the 4th inductor 22.The 6th inductor 42 and second inductor 12 and the 4th inductor 22 electricity are connected in series.Thus, the 5th inductor 42 is positioned at the back fragment position of second rheostat 32.
In aforesaid second execution mode, insert the 5th and the 6th inductor 41,42 respectively at the back segment of first and second rheostat 31,32.Thus, can suppress the characteristic impedance that caused by first and second rheostat 31,32 descends.
Signal circuit SC2 as Fig. 4～shown in Figure 6, configurablely locates at HDMI cable 3, DVD player 2 or binding post 5,6 (connector).At this moment, can further suppress the characteristic impedance that caused by first and second rheostat 31,32 descends.
Then, by this first and second execution mode, specifically illustrate by first and second rheostat and can the suppression characteristic impedance descend.Here, use the characteristic impedance of TDR (Time DomainReflectometry) method measured signal transmission circuit.So-called TDR method is to send step pulse to transmission line, by the pulse that the discontinuous place of measuring characteristic impedance is reflected, measures the assay method of the characteristic impedance of transmission line.
At first, based on Fig. 8 the mensuration environment of using the TDR method is described.Shown in Figure 8 respectively measuring in the environment, high-speed oscilloscope 50 is connected by transmission line 54 with receiver IC52.Transmission line 54 has coaxial cable 56 and signal circuit 58.High-speed oscilloscope 50 has TDR module 51.High-speed oscilloscope 50 is connected with coaxial cable 56 by TDR module 51, and the other end of coaxial cable 56 is connected with signal circuit 58.The other end of signal circuit 58 is connected with receiver IC52.
As high-speed oscilloscope 50, use Agilent Technologies (Agilent Technologies, Inc.) the Agilent86100 wide-band oscilloscope of Sheng Chaning.As TDR module 51, the 54754 differential TDR plug-in modules of using Agilent Technologies to produce.Receiver IC52 has infinitely-great input impedance when power supply disconnects, 100% reflection is from the signal of high-speed oscilloscope 50.Coaxial cable 56 is made of 2 differential signal lines, has the characteristic impedance of 50 Ω respectively.So the characteristic impedance of coaxial cable 56 integral body is 100 Ω.
Below, the assay method of TDR method is described based on Fig. 8 and Fig. 9.At first, high-speed oscilloscope 50 produces incident voltage step Ei, and this incident voltage step Ei is outputed to transmission line 54.When not having the discontinuity point of characteristic impedance on the transmission line 54, incident voltage step Ei directly is reflected at receiver IC52.At this moment, in high-speed oscilloscope 50, shown in (a) among Fig. 9, only represent incident voltage step Ei.On the other hand, when there is discontinuous place in the characteristic impedance of transmission line 54, be reflected in the part of its discontinuous place incident voltage step.At this moment, at high-speed oscilloscope 50, shown in (b) among Fig. 9, reflected wave Er is appended and is illustrated in by algebraically among the incident voltage step Ei.By this result, can obtain the position at the discontinuous place of characteristic impedance and the value of characteristic impedance.That is, can obtain the position at the discontinuous place of characteristic impedance, simultaneously can obtain characteristic impedance by the value of reflected wave Er at discontinuous place by the time T that is measured to reflected wave Er.
As common-mode filter, use ACM2012D-900 (TDK Corp.'s system).The characteristic impedance of ACM2012D-900 is 100 Ω.The disconnection frequency of ACM2012D-900 is 3.5GHz.For first and second rheostat, use AVR161A1R1 (TDK Corp.'s system).The static capacity of AVR161A1R1 is 1.1pF.The the 3rd～the 6th inductor uses MLK1005 series (TDK Corp.'s system).
Measurement result is illustrated among Figure 10～Figure 12.
With reference to Figure 10, characteristic I1 has signal circuit 58, first and second rheostat, does not have the measurement result of common-mode filter and the 3rd～the 6th inductor.By characteristic I1 as can be known, be subjected to first and second rheostatic influencing characterisitic impedance and descend, produce the impedance that do not match.
Characteristic I2 is that signal circuit 58, first and second rheostat and common-mode filter are arranged, and does not have the measurement result of the 3rd～the 6th inductor.Constituting signal circuit 58 places, interval on the lead-out terminal of common-mode filter and the transmission line of first and second rheostatic input terminal, the i.e. long 23ps that is set at of time between the lead-out terminal of common-mode filter and first and second the rheostatic input terminal.
By characteristic I2 as can be known, although in the scope of 100 Ω ± 15%, still being subjected to first and second rheostatic influencing characterisitic impedance, the characteristic impedance of signal circuit 58 descends.
Characteristic I3～characteristic I5 is when signal circuit 58 has first and second rheostat, common-mode filter and the 3rd and the 4th inductor, the measurement result when promptly the signal circuit SC1 structure of signal circuit 58 and above-mentioned first execution mode is identical.Characteristic I3 is the result that inductance value at the 3rd and the 4th inductor is measured during for 1.0nH.Characteristic I4 is the result that inductance value at the 3rd and the 4th inductor is measured during for 1.5nH.Characteristic I5 is the result that inductance value at the 3rd and the 4th inductor is measured during for 2.2nH.Constituting signal circuit 58 places, the interval of the input terminal of the lead-out terminal of common-mode filter and the 3rd and the 4th inductor on transmission line, the i.e. long 20ps that is set at of time between the input terminal of the lead-out terminal of common-mode filter and the 3rd and the 4th inductor.Equally, the lead-out terminal of the 3rd and the 4th inductor and first and second interval of rheostatic input terminal on transmission line, the i.e. long 0ps that is set at of time between the lead-out terminal of the 3rd and the 4th inductor and first and second the rheostatic input terminal.
By characteristic I3～I5 as can be known, can suppress the decline of the characteristic impedance that causes by first and second rheostatic influence.
By characteristic I5 as can be known, when the inductance value of the 3rd and the 4th inductor was 2.2nH, though descend in first and second rheostatic position characteristic impedance, the characteristic impedance of other positions uprised.The inventor thinks that producing position that such characteristic impedance uprises results from the inductance value of the 3rd and the 4th inductor.So, the preferred the 3rd and the inductance value of the 4th inductor be 1～2nH.
Then, with reference to Figure 11.Characteristic I6 and characteristic I7, being when signal circuit 58 has first and second rheostat, common-mode filter and the 3rd～the 6th inductor, promptly is the measurement result when the signal circuit SC2 of signal circuit 58 and above-mentioned second execution mode has same structure.Characteristic I6 is the result that inductance value at the 3rd～the 6th inductor is measured during for 1.0nH.Characteristic I7 is that the inductance value at the 3rd and the 4th inductor is 1.0nH, and the measurement result when making the 5th and the 6th inductor be branch road (by pass).Constituting signal circuit 58 places, the interval of the input terminal of the lead-out terminal of common-mode filter and the 3rd and the 4th inductor on transmission line, the i.e. long 0ps that is set at of time between the input terminal of the lead-out terminal of common-mode filter and the 3rd and the 4th inductor.Equally, the lead-out terminal of the 3rd and the 4th inductor and first and second interval of rheostatic input terminal on transmission line, the i.e. long 0ps that is set at of time between the lead-out terminal of the 3rd and the 4th inductor and first and second the rheostatic input terminal.Equally, the interval of input terminal on transmission line of first and second rheostatic input terminal and the 5th and the 6th inductor, the i.e. long 0ps that is set at of time between the input terminal of first and second rheostatic input terminal and the 5th and the 6th inductor.
By characteristic I6 as can be known, can further suppress the decline of the characteristic impedance that causes by first and second rheostatic influence.
Then, with reference to Figure 12.Characteristic I8～I10, being when signal circuit 58 has first and second rheostat, common-mode filter and the 3rd～the 6th inductor, promptly is the measurement result when the signal circuit SC2 of signal circuit 58 and above-mentioned second execution mode has same structure.Characteristic I8 is that the inductance value at the 3rd and the 4th inductor is 1.5nH, the result that the inductance value of the 5th and the 6th inductor is measured during for 1.0nH.Characteristic I9 is the result that inductance value at the 3rd～the 6th inductor is measured during for 1.5nH.Characteristic I10 is that the inductance value at the 3rd and the 4th inductor is 1.5nH, and the measurement result when making the 5th and the 6th inductor be branch road.Constituting signal circuit 58 places, the interval of the input terminal of the lead-out terminal of common-mode filter and the 3rd and the 4th inductor on transmission line, the i.e. long 0ps that is set at of time between the input terminal of the lead-out terminal of common-mode filter and the 3rd and the 4th inductor.Equally, the lead-out terminal of the 3rd and the 4th inductor and first and second interval of rheostatic input terminal on transmission line, the i.e. long 0ps that is set at of time between the lead-out terminal of the 3rd and the 4th inductor and first and second the rheostatic input terminal.Equally, the interval of input terminal on transmission line of first and second rheostatic input terminal and the 5th and the 6th inductor, the i.e. long 0ps that is set at of time between the input terminal of first and second rheostatic input terminal and the 5th and the 6th inductor.
By characteristic I8 and I9 as can be known, can further suppress the decline of the property impedance that causes by first and second rheostatic influence.
By above narration, can confirm the serviceability of this first and second execution mode.
By the said determination result as can be known, the inductance value of the 3rd～the 6th inductor, preferably less than 10nH, 1～2nH more preferably.This is that the inductance value of the 3rd～the 6th inductor can produce the position that characteristic impedance uprises, and causes impedance matching insufficient because as mentioned above.
The interval of the input terminal of the lead-out terminal of common-mode filter and the 3rd and the 4th inductor on transmission line, the lead-out terminal of the 3rd and the 4th inductor and first and second interval of rheostatic input terminal on transmission line, and the interval of input terminal on transmission line of first and second rheostatic input terminal and the 5th and the 6th inductor, short more good more.This is because the transmission line (for example, the wire pattern of substrate) between each terminal has inductance composition and capacitive component, and these inductance compositions and capacitive component are the main causes that hinders impedance matching.
When using common-mode filter, between holding wire, connect capacitor (for example, opening communique 2004-No. 40444) sometimes with reference to the Japan Patent spy as noise filter.But, when in this first and second execution mode, between holding wire, being connected with capacitor, can producing unwanted capacitive component, thereby can't reach the purpose of impedance matching.So, in this first and second execution mode, do not connect capacitor between holding wire.
More than, preferred forms of the present invention is illustrated, but the present invention not only is defined in these execution modes.For example, signal circuit SC1, SC2 are not limited to above-mentioned position, also can enter the front of the initial circuit of Digital Television 1 by after DVD player 2 outputs.DVD player 2 also can be other a source machine such as PC, set-top box.HDMI cable 3 also can be the cable corresponding to specifications such as DVI, USB, IEEE.Digital Television 1 also can be other a receiver such as LCD monitor and projector.
In first and second execution mode, use rheostat as first and second capacitive element, but also can use capacitive element such as Zener diode as first and second capacitive element.
As common-mode filter 10, except using 2 leads with mutual insulating FERRITE CORE is twined the coil form common-mode filter of a few formations, also can use the cascade type common-mode filter or form the cascade type common-mode filter of the wire pattern that technology forms by film.
When the input and output terminal of common-mode filter 10 is made of metal terminal electrode, also can be with this terminal electrode as the 3rd and the 4th inductor 21,22.At this moment, need set the size of terminal electrode (for example, electrode width etc.) in order to obtain above-mentioned resistance value.
Find out that from detailed description of the present invention the present invention can carry out the variation of multiple mode.These change is not to the deviating from of aim of the present invention and scope, and for a person skilled in the art, conspicuous these are revised all in the scope of following claim.
Claims (6)
1. a signal circuit is the signal circuit that connects the high speed differential transmission road of HDMI specification, it is characterized in that having:
Mutual magnetic-coupled first and second inductor;
Be positioned at the back segment of described first inductor, first capacitive element that is connected in parallel with this first inductor electricity;
Be positioned at the back segment of described second inductor, second capacitive element that is connected in parallel with this second inductor electricity;
Between described first inductor and described first capacitive element, the 3rd inductor that is connected in series with the described first inductor electricity;
Between described second inductor and described second capacitive element, the 4th inductor that is connected in series with the described second inductor electricity,
Temporal length between the input terminal of the lead-out terminal of described first inductor and described the 3rd inductor is set at 0～20ps,
Temporal length between the input terminal of the lead-out terminal of described second inductor and described the 4th inductor is set at 0～20ps,
Temporal length between the input terminal of the lead-out terminal of described the 3rd inductor and described first capacitive element is set at 0ps,
Temporal length between the input terminal of the lead-out terminal of described the 4th inductor and described second capacitive element is set at 0ps,
The described the 3rd and the inductance value of the 4th inductor be 1～2nH,
Characteristic impedance is in the scope of 100 Ω ± 15%.
2. a signal circuit is the signal circuit that connects the high speed differential transmission road of HDMI specification, it is characterized in that having:
Mutual magnetic-coupled first and second inductor;
Be positioned at the back segment of described first inductor, first capacitive element that is connected in parallel with this first inductor electricity;
Be positioned at the back segment of described second inductor, second capacitive element that is connected in parallel with this second inductor electricity;
Between described first inductor and described first capacitive element, the 3rd inductor that is connected in series with the described first inductor electricity;
Between described second inductor and described second capacitive element, the 4th inductor that is connected in series with the described second inductor electricity;
Be positioned at the back segment of described first capacitive element, the 5th inductor that is connected in series with described the 3rd inductor electricity;
Be positioned at the back segment of described second capacitive element, the 6th inductor that is connected in series with described the 4th inductor electricity,
Temporal length between the input terminal of the lead-out terminal of described first inductor and described the 3rd inductor is set at 0～20ps,
Temporal length between the input terminal of the lead-out terminal of described second inductor and described the 4th inductor is set at 0～20ps,
Temporal length between the input terminal of the lead-out terminal of described the 3rd inductor and described first capacitive element is set at 0ps,
Temporal length between the input terminal of the lead-out terminal of described the 4th inductor and described second capacitive element is set at 0ps,
Temporal length between the input terminal of the input terminal of described first capacitive element and described the 5th inductor is set at 0ps,
Temporal length between the input terminal of the input terminal of described second capacitive element and described the 6th inductor is set at 0ps,
The described the 3rd and the inductance value of the 4th inductor be 1～2nH,
The described the 5th and the inductance value of the 6th inductor be 1～2nH,
Characteristic impedance is in the scope of 100 Ω ± 15%.
3. signal circuit as claimed in claim 1 or 2 is characterized in that:
Described first and second capacitive element is a rheostat.
4. electronic equipment with claim 1 or 2 described signal circuits.
5. cable with claim 1 or 2 described signal circuits.
6. connector with claim 1 or 2 described signal circuits.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2004260168A JP3962735B2 (en) | 2004-09-07 | 2004-09-07 | Signal transmission circuit, electronic equipment, cable, and connector |
| JP2004260168 | 2004-09-07 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1747250A CN1747250A (en) | 2006-03-15 |
| CN100474847C true CN100474847C (en) | 2009-04-01 |
Family
ID=35995615
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN200510098776.2A Active CN100474847C (en) | 2004-09-07 | 2005-09-07 | Signal transmission circuit, electronic device, cable, and connector |
Country Status (4)
| Country | Link |
|---|---|
| US (1) | US7557676B2 (en) |
| JP (1) | JP3962735B2 (en) |
| CN (1) | CN100474847C (en) |
| TR (1) | TR200503531A2 (en) |
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| CN100429878C (en) * | 2006-06-01 | 2008-10-29 | 北京工业大学 | Time-domain network measuring system and method based on wideband sampling oscilloscope |
| KR101432846B1 (en) * | 2006-11-07 | 2014-08-26 | 소니 주식회사 | Electronic devices and cable devices |
| EP1975949B1 (en) * | 2007-03-30 | 2015-03-18 | Abb Research Ltd. | A field grading material |
| WO2008127023A1 (en) | 2007-04-11 | 2008-10-23 | Innochips Technology Co., Ltd. | Circuit protection device and method of manufacturing the same |
| KR100844151B1 (en) | 2007-04-11 | 2008-07-07 | 주식회사 이노칩테크놀로지 | Circuit protection device and manufacturing method thereof |
| CN101667727B (en) * | 2008-09-05 | 2012-11-21 | 群康科技(深圳)有限公司 | Interface electrostatic protection circuit |
| US8422190B2 (en) * | 2008-09-30 | 2013-04-16 | Tdk Corporation | Composite electronic device, manufacturing method thereof, and connection structure of composite electronic device |
| JP4835699B2 (en) * | 2009-01-22 | 2011-12-14 | Ｔｄｋ株式会社 | High-speed digital transmission circuit |
| KR101915961B1 (en) * | 2011-09-06 | 2019-01-31 | 삼성전자주식회사 | electronic device and board usable in the electronic device |
| US9244511B2 (en) * | 2012-03-28 | 2016-01-26 | Echostar Uk Holdings Limited | Transient electrical load decoupling for a direct current power supply |
| US9219463B2 (en) * | 2013-02-06 | 2015-12-22 | Intel Corporation | Hybrid common mode choke |
| US9907159B2 (en) * | 2016-07-12 | 2018-02-27 | Fluke Corporation | Plug connector for tuning crosstalk and return loss |
| CN107317134A (en) * | 2017-06-30 | 2017-11-03 | 上海青橙实业有限公司 | USB attachment means, USB fabric and terminal |
| WO2022168922A1 (en) * | 2021-02-04 | 2022-08-11 | パナソニックＩｐマネジメント株式会社 | Electronic control device |
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| JPH02135677A (en) | 1988-11-15 | 1990-05-24 | Mitsubishi Electric Corp | Connector for signal connection |
| US5083101A (en) * | 1990-01-03 | 1992-01-21 | Integrated Power Components | Integrated electromagnetic interference filter |
| US5095291A (en) * | 1990-11-08 | 1992-03-10 | North Hill Electronics, Inc. | Communication filter for unshielded, twisted-pair cable |
| US5313176A (en) * | 1992-10-30 | 1994-05-17 | Motorola Lighting, Inc. | Integrated common mode and differential mode inductor device |
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-
2004
- 2004-09-07 JP JP2004260168A patent/JP3962735B2/en not_active Expired - Lifetime
-
2005
- 2005-08-25 US US11/210,895 patent/US7557676B2/en active Active
- 2005-09-05 TR TR2005/03531A patent/TR200503531A2/en unknown
- 2005-09-07 CN CN200510098776.2A patent/CN100474847C/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN1747250A (en) | 2006-03-15 |
| JP3962735B2 (en) | 2007-08-22 |
| US20060049894A1 (en) | 2006-03-09 |
| JP2006080678A (en) | 2006-03-23 |
| US7557676B2 (en) | 2009-07-07 |
| TR200503531A2 (en) | 2006-04-21 |
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